Light sources may comprise light-emitting diodes (LED) or other point-like light sources. The small size of LEDs enables customization of light patterns which can be provided by means of light emitting assemblies comprising light collimation structure in order to shape the resulting light beam. For automotive adaptive drive beam (ADB) systems or matrix headlamps such pre-collimated optics with an air gap between collimator and light source are often used. The efficiency of such optical systems strongly depends on the distance between collimator and light source. It would be desirable to obtain a more efficient light emitting assembly providing a higher luminance with a more predictable emission color.
U.S. Pat. No. 8,328,403 B1 discloses a light-guide illumination device and system comprising a light source, a light redirecting slab, an air gap and a light guide assembly. U.S. Pat. No. 5,396,350 A discloses a backlighting apparatus comprising light sources and a slab waveguide. An array of microprisms is provided at the light entrance face of the slab waveguide. DE 10 2014 200369 A1 discloses a light guide with an array of micro-optics at the light entrance face.